Strawberry imac G3 won't power on

Is this iMac the one with CD's that are loaded on a "tray" or into a "slot"?

If "tray," and nothing else works, you may be able to get it going by pressing the little black button to the right of the CPU card "cage," at the edge of the motherboard. It's the "master reset" button. Hold it down for a few seconds. If you have upgrade your RAM, you will know how to disassemble the iMac to see that button. If not, please post again.

FYI - A better way to force a restart is to poke a straight paper clip into the little hole next to where the USB ports are located (the top hole with the triangle, I believe). Pulling the plug out can have unintended results.

Gadzooks - I'm sounding like a broken record! You may have something as simple as a dead PRAM battery. Unplugging the machine possibly drained it of it's last bit of power. The "Soft Start" circuit won't work with a dead battery, so the Mac just sits there.

Battery info. here.